scholarly journals The Domain and Microstructure of Resin-Bonded Magnets

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2849
Author(s):  
Marcin Jan Dośpiał
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Size Distribution ◽  
Domain Structure ◽  
Grain Size Distribution ◽  
Exchange Interactions ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Scanning Electron

This paper presents domain and structure studies of bonded magnets made from nanocrystalline Nd-(Fe, Co)-B powder. The structure studies were investigated using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Mössbauer spectroscopy and X-ray diffractometry. On the basis of performed qualitative and quantitative phase composition studies, it was found that investigated alloy was mainly composed of Nd2(Fe-Co)14B hard magnetic phase (98 vol%) and a small amount of Nd1.1Fe4B4 paramagnetic phase (2 vol%). The best fit of grain size distribution was achieved for the lognormal function. The mean grain size determined from transmission electron microscopy (TEM) images on the basis of grain size distribution and diffraction pattern using the Bragg equation was about ≈130 nm. HRTEM images showed that over-stoichiometric Nd was mainly distributed on the grain boundaries as a thin amorphous border of 2 nm in width. The domain structure was investigated using a scanning electron microscope and metallographic light microscope, respectively, by Bitter and Kerr methods, and by magnetic force microscopy. Domain structure studies revealed that the observed domain structure had a labyrinth shape, which is typically observed in magnets, where strong exchange interactions between grains are present. The analysis of the domain structure in different states of magnetization revealed the dynamics of the reversal magnetization process.

Transmission electron microscopy and high resolution scanning electron microscopy of Co-Ni-Pt thin film magnetic recording media

1989 ◽  
Vol 47 ◽  
pp. 570-571
Author(s):  
L. Chan ◽  
T. Yamashita ◽  
R. Sinclair
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Hysteresis ◽  
Exchange Interactions ◽  
Magnetic Media ◽  
Transmission Electron ◽  
Hysteresis Properties ◽  
Scanning Electron

In thin film magnetic media, the magnetic hysteresis properties and micromagnetic domain behavior are strongly influenced by both interparticle exchange interactions and by magnetostatic interactions. The exchange interactions are short-range in nature; therefore, they are very sensitive to interparticle separation. Consequently, the magnetic hysteresis properties and the recording behavior of the thin film magnetic media can be drastically altered by the introduction of grain separation during the film deposition process. In this study, thin film media of a CoNiPt alloy of one composition was processed under two different conditions. Transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HRSEM) were used to investigate and explain the difference in magnetic hysteresis characteristics of the films.The structure of the thin film media consisted of a 600 Å thick CoNiPt alloy sputtered on textured 130mm diameter NiP-plated aluminum substrates. A single sputtering parameter was varied to produce two types of films, labelled type I and type II, which exhibited significant differences in their magnetic recording characteristics.

scholarly journals Plugging A Small Hole

1997 ◽  
Vol 5 (1) ◽  
pp. 3-4
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nuclear Pore ◽  
Nuclear Pores ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
A Cell ◽  
Scanning Electron

It has long been appreciated that communication between the nucleus and the cytoplasm of a cell occurs through the nuclear pores. Regulation of this communication has remained a mystery. A breakthrough in our understanding of this regulation was recently presented by Carmen Perez- Terzic, Jason Pyle, Marisa Jaconi, Lisa Stehnc-Bittel, and David Clapham of Mayo Clinic. Using field emission scanning electron microscopy (FESEM), transmission electron microscopy, and atomic force microscopy (AFM), they demonstrated the presence of a small plug within the nuclear pore that was present under certain physiologic circumstances. This “plug“ may regulate the movement of molecules through the pore.

Structural features and dopant gradients in Mg2SnXSi1-X ternary compounds

2014 ◽  
Vol 1642 ◽  
Author(s):  
E. Hatzikraniotis ◽  
G.S. Polymeris ◽  
C.B. Lioutas ◽  
A. Burkov ◽  
E-C. Stefanaki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Fourier Transform ◽  
Structural Features ◽  
Free Carrier ◽  
Ternary Compounds ◽  
Transmission Electron ◽  
Scanning Electron

ABSTRACTIn the present work, a comparative study is attempted, dealing with the influence of the grain size distribution on the microstructure and the free carrier concentration in Mg2SnXSi1-X (x=0.2) ternary compounds doped with Sb. Structural in-homogeneities were monitored by using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) as well as Fourier transform infrared spectroscopy (FTIR) in the reflectivity mode.

Grain size distribution of nanocrystalline systems

2005 ◽  
Vol 20 (4) ◽  
pp. 353-358 ◽  
Author(s):  
Paolo Scardi ◽  
Matteo Leoni ◽  
Diego G. Lamas ◽  
Edgardo D. Cabanillas
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Diffraction Pattern ◽  
Size Distribution ◽  
Domain Size ◽  
Typical Case ◽  
Line Broadening ◽  
Transmission Electron ◽  
Pattern Modeling

The diffraction pattern of nanocrystalline Ce0.9Zr0.1O2 was analyzed by whole powder pattern modeling, a recently proposed method for the study of line broadening. The main result in this typical case of study—the crystalline domain size distribution—matches closely the corresponding information obtained by transmission electron microscopy. Further information on nature and content of lattice defects is also discussed.

The Influence of Deformation the Corrosion Resistance of Titanium Grade2

2015 ◽  
Vol 227 ◽  
pp. 27-30 ◽  
Author(s):  
Marta Zwolińska ◽  
Agata Sotniczuk ◽  
Krzysztof Topolski ◽  
Andrzej Królikowski ◽  
Halina Garbacz
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Extrusion Direction ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Transmission Electron

Severe Plastic Deformation (SDP) processes including Hydroextrusion (HE) causes the change of the mechanical properties by the introduction of a large number of defects and significant refinement of the microstructure. During the initially stages of HE microstructure becomes more elongated according to the extrusion direction. Only after a certain deformation, grains become more equiaxed. Present studies are intended to determine the influence of the titanium Grade2 microstructure and grain size distribution on its corrosion properties. All corrosion tests were conducted in a 0.9 % NaCl solution at room temperature. Electrochemical Impedance Spectroscopy (EIS) was measured after 2 and 24 hours. Also Potentiodynamic Polarization was conducted after 24 hours. Microstructures were reviled using Scanning Electron Microscopy and Transmission Electron Microscopy. Grain size distribution was determined using the program Micrometer . The results confirmed formation of titanium dioxide and very good corrosion properties of titanium Grade2 at all stages of hydrostatic extrusion.

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